The disc of D671X pneumatic butterfly valve is installed in the diameter direction of the pipelines. In the cylindrical corridors of the valve body,the disc revolves around the axis with an angle between 0°and 90°. The valves are in complete open condition when the disc revolve to 90°.

Butterfly valves have advantages such as simple structure,small size,light weight,and only with a few parts. But it can be rapidly opened and closed easily only by revolving 90°.

While the valves are in fully open condition,the disc thickness is the only drag force when the medium flows through the valve body, So the pressure generated is very small. In conclusion, it have special advantage in controlling the flow rate.

The normal pneumatic butterfly valves are in wafer type, LT type and flanged type. For the wafer type butterfly valves, the valves are linked between two pipelines by stud bolt. For the flanged type butterfly valves,the flanges on the two ends of the valves are linked to the pipeline flanges. The LT type butterfly valves are often used at the end of the pipelines.